The research proposed has three primary objectives. The first is to identify the effects of marijuana and cocaine use on the marriage and divorce rates of young adults. The second is to examine whether marijuana and cocaine use are factors associated with the probability of being a single parent. The third is to investigate the relationship between marijuana and cocaine use, and participation in the Aid to Families with Dependent Children (AFDC) program. The three objectives are closely related due to the intimate connection between an individual's marriage and fertility plans, and the impact these variables have on AFDC participation. This, the broad purpose of this project is to provide new information concerning the extent to which the most commonly used types of illicit drugs are affecting the family structure. The family plays a vital role in our society and is an important economic institution. One of the most significant, and long lasting contributions of the family, is the production and rearing of children. The family has the primary responsibility for the nurturing and development of children, and there is a growing public concern regarding the state and condition of our families. The deterioration of the family is frequently cited as a potential cause of many of the current problems confronting children. The role that illicit drug use plays in determining family structure is relatively unknown, and the purpose of this research is to fill this gap in our knowledge. The data that will be used in this project will come from the youth cohort of the National Longitudinal Survey (NLS), which is a longitudinal survey of the labor market experiences of young adults (Center for Human Resource Research 1990). The starting year of the survey was 1979 and included an initial sample of approximately 12500 youths aged 14-21 at the time. The survey has been updated each year since 1979 with a broadening array of purposes and questions. The data contain detailed information on a respondent's labor market experience, family and personal background, and illicit drug use. Central to the purposes of this paper are the questions related to respondent's illicit drug use. In 1984, and again in 1988 the respondent was asked questions about their use of several illicit drugs, most notably marijuana and cocaine. The proposed research will obtain estimates of the effects of illicit drug use on family structure using both cross sectional and longitudinal samples drawn from the NLS. Several statistical procedures will be used to analyze the data including multinomial logit models, duration or hazard models, and simpler descriptive methods.